Swash plate type compressor

ABSTRACT

A swash plate type compressor comprising a cylindrical casing, a pair of cylinder blocks disposed in the cylindrical casing, and three double-acting pistons being disposed within the cylinder blocks and reciprocated by means of a swash plate. Each of the cylinder blocks is provided with a high pressure passageway and a low pressure passageway, and a silencing chamber is formed on the cylindrical casing by means of a cover member which is mounted in a gas-tight manner on the cylindrical casing. The silencing chamber communicates with the high pressure passageway through a silencing pipe. An alternative embodiment utilizes a spring member for communicating the silencing chamber with the high pressure passageway.

United States Patent [191.

Nemoto et al.

SWASH PLATE TYPE COMPRESSOR Inventors: MamoruNemoto, Katsuta; Seijiro Tani, Hitachi, both of Japan Assignee: Hitachi, Ltd., Tokyo, Japan Filed: Apr. 24, 1972 Appl. No.: 247,024

Related US. Application Data [63] Continuation-impart of Scr. No. 87,896, Nov. 9,

1970, abandoned.

[52] US. CL... 417/269, 91/502, 92/71, 417/312 [51] Int. Cl. F041) 1/16, F04b 21/00 [58] Field of Search 417/312, 269; 91/502; 92/69, 70, 71, 72

[56] References Cited 7 UNITED STATES PATENTS 3,577,891 5/1971 Nemoto et a1. 92/72 1,367,914 2/1921 Larsson 91/502 X 2,136,098 11/1938 Browne 417/312X Jan. 15, 1974 3,057,545 10/1962 Ransom etal. ..4l7/269 3,542,493 11/1970 Alderson ..417/312 Primary Examiner-Al Lawrence Smith Assistant Examiner-Richard Sher Att0rneyPaul M. Craig, Jr. et a1.

[57] ABSTRACT A swash plate type compressor comprising a cylindrical casing, a pair of cylinder blocks disposed in the cylindrical casing, and three double-acting pistons being disposed within the cylinder blocks and reciprocated by means of a swash plate. Each of the cylinder blocks is provided with a high pressure passageway and a low pressure passageway, and a silencing chamber is formed on the cylindrical casing by means of a cover member which is mountedin a gas-tight manner on the cylindrical casing. The silencing chamber communicates with the high pressure passageway through a silencing pipe. An alternative embodiment utilizes a spring member for communicating the silencing chamber with the high pressure passageway.

25 Claims, 5 Drawing Figures PAIENTE JAM 5 IBM SHEET 1 0f 3 INVENTORS AMoRU NEMOTO AND SEFJiRO TAN] BY Cvaia, AntoneuL, Stewart w I ATTORNEYS PATENTED JAN 1 5 I91 SHEET 2 0F 3 FIG. 2

FIG. 3 PRIOR ART INVENTORS MAMQRU EMoTo AND SEITIRO TAN BY CY S, Anlbneui, Stewart ATTORNEYS of our earlier copending application Ser. No. 87,896, filed Nov. 9, 1970, now abandoned.

BACKGROUND OF THE INVENTION The present invention relates to an improvement in a swash plate type compressor and, more particularly, to an improved swash plate compressor having a reduced size, small noise characteristics and being manufactured easily. 7

A swash plate type compressor is adapted for use in an air conditioning system for an automotive vehicle as a result of the advantages that a variation in torque is small because the number of cylinder bores per shaft can be increased, that the noise is relatively small, and that the compressor can be formed in an elongated cylindrical shape so as to facilitate mounting thereof within the engine room of the vehicle. In particular, a rotary swash plate compressor actually used for air conditioning system in an automotive vehicle or the like comprises three double-acting pistons and a swash plate fixedly mounted on a single drive shaft, so that the pressure pulsation is suppressed to some extent by the mutual action of three double-acting pistons.

However, with such a construction alone it is impossible to completely absorb the pressure pulsation of the compressor, and the compressor still generates a pulsating sound providing a source of noise. When the compressor is used in an air conditioning system, the noise from the compressor is smaller than that from the engine when in high speed operation, but the former becomes larger than the latter when the engine is in low speed operation. This noise also takes place due to vibration of a pipe connected to a refrigerant discharging side of the compressor, It is obviously desirable to reduce such noise to a minimum.

As a manner of eliminating or reducing the noise, silencing means have heretofore been provided downstream of the outlet at the'high pressure side of the compressor. In this manner, however, the mounting position of the silencing meansin the engine room and the side of the silencing means are subjected to a limitation, and it has been impossible or very difficult to incorporate the silencing means in, especially, a small sized automotive vehicle so as to have a sufficient silencing effect.

SUMMARY or THE INVENTION of noise occurrence. 1

The foregoing problems have been solved in accordance with the present invention by providing a cylindrical casing, a pair of cylinder blocks disposed in the cylindrical casing, and three double-acting pistons being disposed within the cylinder blocks and recipro- BRIEF DESCRIPTION OF THE DRAWING The above mentioned objects and other objects and features of the invention'will be apparent from the following description taken inconjunction with the attached drawing in which:

FIG. 1 is a horizontal sectional view of a swash plate compressor according to the present invention;

FIG. 2 is a sectional view taken on the line Il-II of FIG. 1;

FIG. 3 is a perspective view of a pair of the conventional cylinder blocks; 1

, FIG. 4 is a horizontal partial sectional view of a swash plate compressor showing a second embodiment of the present invention; and

FIG. 5 is a partial sectional view taken along the line 'V-V of FIG. 4.

DETAILED DESCRIPTION OF THE DRAWING Referring now to the drawing and, in particular, to FIG. 1, a pair of cylinder blocks 1F, 1R are mounted in a cylindrical casing 7. Each of the cylinder blocks has three piston cylinders l8, a passageway 20F, 20R for a high pressure refrigerant gas and a passageway l l for a lowpressure refrigerant gas. The drive shaft 12 which is provided with a swashplate 14, is rotatably supported by means of bearings 13 in the cylinder blocks which are oppositely faced to each other. Three double-acting pistons 4 slidably disposed in the cylinders are supported, by means of a series of ball bearings 16 and shoes 15, to the swash plate 14. Rotation of the swash plate 14 causes reciprocation of the pistons 4.

Separate cylinder head plates 2F, 2R provided with check valves or non-return valves (not shown) are provided adjacent each end of the cylinder blocks 1F, 1R, as shown. The cylinder head housings 3F, 3R are secured to the cylinder blocks in a suitable manner through the cylinder head plate 2F, 2R. Each of the housings has a high pressure gas passageway 5F, SR and a low pressure gas passageway 10F, 10R and these passageways are angularly shaped around the drive shaft 12. The passageways 5F, 5R communicate with a respective high pressure gas passageway 20F, 20R formed in the cylinder blocks, and the low pressure gas passageway 10R communicates with an intake pipe 9 and a passageway 11 communicates between the passageway 10F, 10R.

A portion of low pressure refrigerant gas supplied through the intake pipe 9 is sucked into the respective cylinder 18 facing the passageway 10R, and the other partis sucked into the cylinder through the passageway 11 by virtue of reciprocating movement of the pistons. The refrigerant gas is supplied to the cylinders only while the cavity of the cylinder is expanding. This is done by the action of check valves (not shown) provided in the cylinder head plates 2F, 2R. The refrigerant gassucked into the cylinder bores is then compressed by reciprocationof the pistons, and the compressed gas is discharged from the cylinder through the check valves provided in the cylinder head plates. The discharged compressed gas of high. pressure is supplied to the passageway 20F, 20R through the passageway 5F, SR and window 19F, 19R.

The compressed gas in the passageway 20F, 20R is then ejected into a silencing chamber 26 through a silencing pipe 21 having a relatively small diameter as compared with the volume of the silencing chamber 26 so as to effectively cause the silencing action due to a sudden change of volume of the compressed gas. The

refrigerant gas ejected into the silencing chamber is discharged through a discharge port 27 to a condensor (not shown) of the air conditioning system.

The swash plate compressor according to the present invention is characterized by the fact that the silencing chamber 26 is formed by means of a cover member 24 which is mounted in a gas-tight manner on the cylindrical casing 7 at a position intermediate between a pair of high pressure gas passageways. As shown in the drawing, the silencing chamber 26 is so located as to be in the intermediate position of the cylinder blocks, i.e., the silencing chamber is positioned on the junction of the cylinder blocks. As a result of employing such a construction, the pressure pulsation occurring in the refrigeration system is cancelled by virtue ofa collision of the compressed gas which is discharged from silencing chamber since the distances between the discharge port 27 and the outlets of cylinder bores communicating with the passageways 20F, 20R are substantially equal and the influences of pressure pulsations occurring between the two passageways of high pressure become equal.

A cover member 24 is provided with the discharge port 27 at a position substantially intermediate the pair of silencing pipe 21, each having a plurality of small holes in its wall, and is fixedly mounted on the cylindrical casing 7 in a suitable manner such as, forexample, a bolt 41. The silencing pipes 21 are inserted between the cylinder blocks and the cover member so that the outlet of passageway 20R communicates with the silencing chamber 26. The silencing pipes are pressed against the cylinder block through a sealing means, such as, O-shaped ring 22, by means of a resilient member 23. According to the above described construction, the provision of the silencing means can be carried out with remarkable ease. Furthermore, it is a very important advantage that the desired silencing chamber can be provided at the compressor by the small number of the parts.

In general, the compressor is so mounted in the engine room that the periphery of the compressor 'is in contact with air. From this viewpoint, the swash plate type compressor according to the present invention provides an advantage in that the thermal efficiency thereof is increased as compared with the conventional ones because the silencing chamber of the compressor of the invention is formed in the periphery of the cylindrical casing and the cover member can be in contact with air, so that the compressed refrigerant gas which has been warmed by virtue of compression is effectively air-cooled.

On the contrary, as shown in the conventional cylinder blocks of FIG. 3, when the high pressure passageways are disposed in the cylinder blocks 31F, 31R so as to communicate with each other by means of a pipe 36 being inserted in an air-tight manner through the holes provided to the cylinder blocks, an increase in temperature of the cylinder blocks takes place by virtue of passing the compressed refrigerant gas through the cylinder blocks. Accordingly, the increase of the temperature necessarily impairs the thermal efficiency of the compressor.

The embodiment illustrated in FIGS. 4 and 5 differs from the embodiment of FIG. 1 in that a pair of short pipes 38 and a pair of springs 37 are utilized instead of the'pipe members 21 and resilient member 23. The short pipes 38 are gas-tightly supported in the holes formed in the casing.

In this embodiment springs 37 are compressedly inserted between the upper ends of the short pipes 38 and the inner surface of the cover member in order to attain the tight communication between the high pressure gas passageway and the silencing chamber.

This last described arrangement is very easily manufactured at a low cost because it is unnecessary to form small holes which require additional working time and there is minimal breakage of the springs since they can be constructed quite large without adversely affecting the size of the compressor. 7 Further, the springs 37, provide a silencing effect due to the effective throttling of the high pressure gas as it passes through the spring structure.

While the preferred embodiments have been dis- 7 closed herein it will be apparent that many modifications thereof are feasible without departing the spiritof the invention and it is intended that such modifications are also covered by the appended claims.

What we claim is:

1. A swash plate type compressor comprising a. a cylindrical casing member, 7

b. a pair of cylinder blocks disposed in said casing member with said casing member circumferentially surrounding said cylinder blocks along a substantial portion of the length of said cylinder blocks, each cylinder block being provided with at least one cylinder bore,

c. a driving shaft rotatably mounted in said cylinder blocks,

(1. a swash plate fixedly mounted on said driving shaft, I

e. at least one double-acting piston having first and second piston parts, each piston being mounted with said respective first and second piston parts at opposite sides of said swash plate for reciprocation in the respective cylinder bores,

f. cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks, each cylinder head member being provided with an annular partition member fitted on each of said outer ends thereby to define a low pressure gas passageway and a high pressure gas passageway between said cylinder blocks and said cylinder head members, said low pressure gas passageway being operatively communicated with an intake port and the cylinder bores through check valve means for a refrigerant gas, said high pressure gas passageway being operatively communicated with a discharge port and the cylinder bores through check valve means for a compressed refrigerant gas, and

g. a cover member mounted in an air-tight manner directly on said casing member to form a substantial part of a silencing chamber outside of said casing member between said cover member and said casing member at a position intermediate of the outlets of the cylinder bores operatively communicating with said high pressure gas passageway, said silencing chamber being communicating with said high pressure gas passageway through pipe members having a volume smaller than that of said silencing chamber, wherein said pipe members are detachably interposed between said casing member and said cover member, whereby said silencing chamber is communicated with said high pressure gas passageway through an aperture formed in said pipe members. I i

2. A swash plate type compressor according to claim I 11, wherein the high pressure gas passageways and the silencing chamber are operatively communicated with each other by pipe means having a plurality of small holes.

3. A swash plate type compressor according to claim 2, wherein the volume-of the pipe means is relatively small as compared to the volume of the silencing chamber.

4. A swash plate type compressor according to claim 4, wherein the silencing chamber is located at the junction of the cylinder blocks.

5. A swash plate type compressor according to claim 5, wherein the pipe means is inserted between the cylindrical casing and the cover member and pressedly supported by resilient means.

6. A swash plate type compressor according to claim 1, wherein said pipe members are provided with a plurality of small holes.

7. A compressor according to claim 1, wherein inner walls of said casing member directly engage a substantial portion of the circumference of said cylinder blocks to hold said blocks in position in said casing member, wherein a portion of the outwardly facing surface of said casing member is flattened, and wherein said cover member is abuttingly clamped along said flattened portion of said casing member.

8. A swash plate type compressor comprising a. a casing member,

b. a pair of cylinder blocks disposed in said casing member with said casing member circumferentially surrounding said cylinder blocks along a substantial portion of the length of said cylinder blocks, each cylinder block being provided with a plurality of cylinder bores,

c. a driving shaft rotatably mounted in said cylinder blocks and having a swash plate fixedly mounted thereon,

d. a plurality of double-acting pistons, each piston being mounted with respective first and second piston parts at opposite sides of said swash plate for reciprocation in the respective cylinder bores,

e. a pair of cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks, each cylinder head member being provided with an annular partition member for defining a low pressure gas passageway and a high pressure gas passageway between said cylinderblocks and said cylinder head members, said low pressure gas passageway communicating with an intake port for a refrigerant gas and the cylinder bores through check valve means, said high pressure gas passageway communicating with a discharge port for a compressed refrigerant gas having a relatively higher temperature and the cylinder bores through check valve means, and

f. a cover member mounted in an air-tight manner directly on said casing member to form a substantial part of a silencing chamber outside of said casing member between said cover member and said casing member at a position intermediate of the outlets of the cylinder bores operatively communicating with said high pressure gas passageway, said silencing chamber being communicated with said high pressure gas passageway through pipe members having a volume smaller than that of said silencing chamber, wherein said pipe members are interposed between a substantially straight surface of said casing member and an inner surface of said cover member at a position corresponding to an opening of said high pressure gas passageway.

9. A swash plate type compressor according to claim 8, wherein the high and low pressure gas passageways are annularly shaped around the drive shaft.

10. A. swash plate type compressor according to claim 8, wherein said pipe members are provided with a plurality of small holes.

11. In a swash plate type compressor comprising a. a cylindrical casing member,

b. a pair of cylinder blocks fitted in said cylindrical casing member, each cylinder block being provided with three pairs of cylinder bores arranged in a concentric relation,

c. a driving shaft rotatably mounted in a bore formed in said cylinder blocks in the axial direction of said cylinder blocks,

(1. a swash plate fixedly mounted on said driving shaft,

e. three double-acting pistons, each piston being mounted with respective first and second piston parts on opposite sides of said swash plate for reciprocation in the respective bores,

f. a pair of cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks, each head member being provided with an annular partition member for defining a pair of low and high pressure gas passageways between said cylinder blocks and said cylinder head members, said low pressure gas passageways being operatively communicated with an intake port for a refrigerant gas and said cylinder bores through check valve means provided in said cylinder head members, said high pressure gas passageways being operatively communicated with a discharge port for a compressed refrigerant gas and said cylinder bores through check valve means provided in said cylinder head members,

g. a cover member having said discharge port and mounted in an air-tight manner on said casing member whereby a silencing chamber is formed between said cover member and said casing member at a position intermediate of the outlets of said cylinder bores operatively communicating with said high pressure gas passageways through a pair of pipe members, the improvement wherein said pipe members having a plurality of small holes are interposed between said cover member and said casing members, said pipe members pressedly supported by resilient means.

12. A swash plate type compressor according to claim 11, wherein the high and low pressure gas passageways are annularly shaped around the drive shaft.

13. A swash plate type compressor according to claim 12, wherein sealing means is provided between the cylinder block and the pipe means, and the resilient means biases the pipe means against the cylinder block through the sealing means.

14. A swash plate type compressor according to claim 11, wherein the volume of the pipe means is relatively small as compared to the volume of the silencing chamber.

15. A swash plate type compressor according to claim 14, wherein the silencing chamber is located at the junction of the cylinder blocks.

16. A swash plate type compressor comprising a. a cylindrical casing member,

b. a pair of cylinder blocks fitted in said cylindrical casing member, each cylinder block being provided with three pairs of cylinder bores arranged in a concentric relation,

(2. a driving shaft rotatably mounted in a bore formed in said cylinder blocks in the axial direction of said cylinder blocks,

d. a swash plate member fixedly mounted on said driving shaft,

e. three double-acting pistons, each piston being mounted with respective first and second piston parts on opposite sides of said swash plate member for reciprocation in the respective cylinder bores,

f. a pair of cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks and provided with an annular partition member for defining a pair of low and high pressure gas passageways between said cylinder blocks and said cylinder head members, said low pressure gas passageways being operatively communicated with an intake for a refrigerant gas and said cylinder bores through first check valve means provided in said cylinder head members, said high pressure gas passageways being operatively communicated with a discharge port for a compressed refrigerant gas and said cylinder bores through second check valve means provided in said cylinder head members,

g. a cover member provided with said discharge port and mounted'in an air-tight manner on said casing member, whereby a silencing chamber is formed between said cover member and easing member at a position intermediate of the outlets of said cylinder bores operatively communicating with said high pressure gas passageways through a pair of resilient members interposed between the inner surface of said cover member and said cylinder blocks through holes formed in said casing members, said resilient members enclosing a smaller volume than said silencing chamber and having a passageway thereby allowing the flowing-out of said compressed refrigerant gas from said high pressure gas passageways to said silencing chamber, whereby an undesirable pressure pulsation occurring in said compressor is effectively absorbed.

17. A compressor according to claim 16, wherein said resilient members comprise coil springs through which the refrigerant gas flows.

being 18. A swash plate type compressor comprising a. a cylindrical casing member,

b. a pair of cylinder blocks disposed in said casing member, each cylinder block being provided with at least one cylinder bore,

c. a driving shaft rotatably mounted in said cylinder blocks,

d. a swash plate fixedly mounted on said driving shaft,

e. at least one double-acting piston having first and second piston parts, each piston being mounted with said respective first and second piston parts at opposite sides of said swash plate for reciprocation in the respective cylinder bores,

f. cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks, each cylinder head member being provided with an annular partition member fitted on each of said outer ends thereby to define a low pressure gas passageway and a high pressure gas passageway between said cylinder blocks and said cylinder head members, said low pressure gas passageway being operatively communicated with an intake port and the cylinder bores through check valve means for a refrigerant gas, said high pressure gas passageway being operatively communicated with a discharge port and the cylinder bores throughcheck valve means for a compressed refrigerant gas, and

g. a cover member mounted in an air-tight manner on said casing member whereby a silencing chamber is formed between said cover member and said casing member at a position intermediate of the outlets of the cylinder bores operatively communicating with said high pressure gas passageway, said silencing chamber being communicated with said high pressure gas passageway through pipe members having a volume smaller than that of said silencing chamber, wherein said pipe members are detachably interposed between said casing member and said cover member, whereby said silencing chamber is communicated with said high pressure gas passageway through an aperture formed in said pipe members, wherein the high pressure gas passageways and the silencing chamber are operatively communicated with each other by pipe means having a plurality of small holes, and wherein the pipe means is inserted between the cylindrical casing member and the cover member and pressedly supported by resilient means.

19. A compressor according to claim 18, wherein the volume of the pipe means is relatively small as compared to the volume of the silencing chamber.

20. A compressor according to claim 19, wherein the silencing chamber is located at the junction of the cylinder blocks.

21. A silencing chamber arrangement for a swash plate type compressor of the type having high pressure gas passageways located at opposite sides of a rotatable swash plate; said arrangement comprising a silencing chamber positioned between said high pressure gas passageways, a discharge port communicating with the silencing chamber for discharging gas from said silencing chamber, and detachable silencing communicating means for communicating each of said high pressure gas passageways with said silencing chamber, said siw said detachable silencing communicating means includes a resilient member and a detachable pipe member, said pipe member having apertures through the side walls thereof through which the gas in the associated high pressure gas passageway flows.

25. An arrangement according to claim 21, wherein said detachable silencing communicating means includes a resilient member for resiliently holding other parts of said communicating means in position, and wherein said high pressure gas passageways are located symmetrically with respect to the volumetric center of said silencing chamber. 

1. A swash plate type compressor comprising a. a cylindrical casing member, b. a pair of cylinder blocks disposed in said casing member with said casing member circumferentially surrounding said cylinder blocks along a substantial portion of the length of said cylinder blocks, each cylinder block being provided with at least one cylinder bore, c. a driving shaft rotatably mounted in said cylinder blocks, d. a swash plate fixedly mounted on said driving shaft, e. at least one double-acting piston having first and second piston parts, each piston being mounted with said respective first and second piston parts at opposite sides of said swash plate for reciprocation in the respective cylinder bores, f. cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks, each cylinder head member being provided with an annular partition member fitted on each of said outer ends thereby to define a low pressure gas passageway and a high pressure gas passageway between said cylinder blocks and said cylinder head members, said low pressure gas passageway being operatively communicated with an intake port and the cylinder bores through check valve means for a refrigerant gas, said high pressure gas passageway being operatively communicated with a discharge port and the cylinder bores through check valve means for a compressed refrigerant gas, and g. a cover member mounted in an air-tight manner directly on said casing member to form a substantial part of a silencing chamber outside of said casing member between said cover member and said casing member at a position intermediate of the outlets of the cylinder bores operatively communicating with said high pressure gas passageway, said silencing chamber being communicating with said high pressure gas passageway through pipe members having a volume smaller than that of said silencing chamber, wherein said pipe members are detachably interposed between said casing member and said cover member, whereby said silencing chamber is communicated with said high pressure gas passageway through an aperture formed in said pipe members.
 2. A swash plate type compressor according to claim 1, wherein the high pressure gas passageways and the silencing chamber are operatively communicated with each other by pipe means having a plurality of small holes.
 3. A swash plate type compressor according to claim 2, wherein the volume of the pipe means is relatively small as compared to the volume of the silencing chamber.
 4. A swash plate type compressor according to claim 4, wherein the silencing chamber is located at the junction of the cylinder blocks.
 5. A swash plate type compressor according to claim 5, wherein the pipe means is inserted between the cylindrical casing and the cover member and pressedly supported by resilient means.
 6. A swash plate type compressor according to claim 1, wherein said pipe members are provided with a plurality of small holes.
 7. A compressor according to claim 1, wherein inner walls of said casing member directly engage a substantial poRtion of the circumference of said cylinder blocks to hold said blocks in position in said casing member, wherein a portion of the outwardly facing surface of said casing member is flattened, and wherein said cover member is abuttingly clamped along said flattened portion of said casing member.
 8. A swash plate type compressor comprising a. a casing member, b. a pair of cylinder blocks disposed in said casing member with said casing member circumferentially surrounding said cylinder blocks along a substantial portion of the length of said cylinder blocks, each cylinder block being provided with a plurality of cylinder bores, c. a driving shaft rotatably mounted in said cylinder blocks and having a swash plate fixedly mounted thereon, d. a plurality of double-acting pistons, each piston being mounted with respective first and second piston parts at opposite sides of said swash plate for reciprocation in the respective cylinder bores, e. a pair of cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks, each cylinder head member being provided with an annular partition member for defining a low pressure gas passageway and a high pressure gas passageway between said cylinder blocks and said cylinder head members, said low pressure gas passageway communicating with an intake port for a refrigerant gas and the cylinder bores through check valve means, said high pressure gas passageway communicating with a discharge port for a compressed refrigerant gas having a relatively higher temperature and the cylinder bores through check valve means, and f. a cover member mounted in an air-tight manner directly on said casing member to form a substantial part of a silencing chamber outside of said casing member between said cover member and said casing member at a position intermediate of the outlets of the cylinder bores operatively communicating with said high pressure gas passageway, said silencing chamber being communicated with said high pressure gas passageway through pipe members having a volume smaller than that of said silencing chamber, wherein said pipe members are interposed between a substantially straight surface of said casing member and an inner surface of said cover member at a position corresponding to an opening of said high pressure gas passageway.
 9. A swash plate type compressor according to claim 8, wherein the high and low pressure gas passageways are annularly shaped around the drive shaft.
 10. A swash plate type compressor according to claim 8, wherein said pipe members are provided with a plurality of small holes.
 11. In a swash plate type compressor comprising a. a cylindrical casing member, b. a pair of cylinder blocks fitted in said cylindrical casing member, each cylinder block being provided with three pairs of cylinder bores arranged in a concentric relation, c. a driving shaft rotatably mounted in a bore formed in said cylinder blocks in the axial direction of said cylinder blocks, d. a swash plate fixedly mounted on said driving shaft, e. three double-acting pistons, each piston being mounted with respective first and second piston parts on opposite sides of said swash plate for reciprocation in the respective bores, f. a pair of cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks, each head member being provided with an annular partition member for defining a pair of low and high pressure gas passageways between said cylinder blocks and said cylinder head members, said low pressure gas passageways being operatively communicated with an intake port for a refrigerant gas and said cylinder bores through check valve means provided in said cylinder head members, said high pressure gas passageways being operatively communicated with a discharge port for a compressed refrigerant gas and said cylinder bores through check valve means provided in said cylinDer head members, g. a cover member having said discharge port and mounted in an air-tight manner on said casing member whereby a silencing chamber is formed between said cover member and said casing member at a position intermediate of the outlets of said cylinder bores operatively communicating with said high pressure gas passageways through a pair of pipe members, the improvement wherein said pipe members having a plurality of small holes are interposed between said cover member and said casing members, said pipe members being pressedly supported by resilient means.
 12. A swash plate type compressor according to claim 11, wherein the high and low pressure gas passageways are annularly shaped around the drive shaft.
 13. A swash plate type compressor according to claim 12, wherein sealing means is provided between the cylinder block and the pipe means, and the resilient means biases the pipe means against the cylinder block through the sealing means.
 14. A swash plate type compressor according to claim 11, wherein the volume of the pipe means is relatively small as compared to the volume of the silencing chamber.
 15. A swash plate type compressor according to claim 14, wherein the silencing chamber is located at the junction of the cylinder blocks.
 16. A swash plate type compressor comprising a. a cylindrical casing member, b. a pair of cylinder blocks fitted in said cylindrical casing member, each cylinder block being provided with three pairs of cylinder bores arranged in a concentric relation, c. a driving shaft rotatably mounted in a bore formed in said cylinder blocks in the axial direction of said cylinder blocks, d. a swash plate member fixedly mounted on said driving shaft, e. three double-acting pistons, each piston being mounted with respective first and second piston parts on opposite sides of said swash plate member for reciprocation in the respective cylinder bores, f. a pair of cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks and provided with an annular partition member for defining a pair of low and high pressure gas passageways between said cylinder blocks and said cylinder head members, said low pressure gas passageways being operatively communicated with an intake for a refrigerant gas and said cylinder bores through first check valve means provided in said cylinder head members, said high pressure gas passageways being operatively communicated with a discharge port for a compressed refrigerant gas and said cylinder bores through second check valve means provided in said cylinder head members, g. a cover member provided with said discharge port and mounted in an air-tight manner on said casing member, whereby a silencing chamber is formed between said cover member and casing member at a position intermediate of the outlets of said cylinder bores operatively communicating with said high pressure gas passageways through a pair of resilient members interposed between the inner surface of said cover member and said cylinder blocks through holes formed in said casing members, said resilient members enclosing a smaller volume than said silencing chamber and having a passageway thereby allowing the flowing-out of said compressed refrigerant gas from said high pressure gas passageways to said silencing chamber, whereby an undesirable pressure pulsation occurring in said compressor is effectively absorbed.
 17. A compressor according to claim 16, wherein said resilient members comprise coil springs through which the refrigerant gas flows.
 18. A swash plate type compressor comprising a. a cylindrical casing member, b. a pair of cylinder blocks disposed in said casing member, each cylinder block being provided with at least one cylinder bore, c. a driving shaft rotatably mounted in said cylinder blocks, d. a swash plate fixedly mounted on said driving shaft, e. at least one double-acting piston having First and second piston parts, each piston being mounted with said respective first and second piston parts at opposite sides of said swash plate for reciprocation in the respective cylinder bores, f. cylinder head members detachably mounted in an air-tight manner on respective oppositely facing outer ends of said cylinder blocks, each cylinder head member being provided with an annular partition member fitted on each of said outer ends thereby to define a low pressure gas passageway and a high pressure gas passageway between said cylinder blocks and said cylinder head members, said low pressure gas passageway being operatively communicated with an intake port and the cylinder bores through check valve means for a refrigerant gas, said high pressure gas passageway being operatively communicated with a discharge port and the cylinder bores through check valve means for a compressed refrigerant gas, and g. a cover member mounted in an air-tight manner on said casing member whereby a silencing chamber is formed between said cover member and said casing member at a position intermediate of the outlets of the cylinder bores operatively communicating with said high pressure gas passageway, said silencing chamber being communicated with said high pressure gas passageway through pipe members having a volume smaller than that of said silencing chamber, wherein said pipe members are detachably interposed between said casing member and said cover member, whereby said silencing chamber is communicated with said high pressure gas passageway through an aperture formed in said pipe members, wherein the high pressure gas passageways and the silencing chamber are operatively communicated with each other by pipe means having a plurality of small holes, and wherein the pipe means is inserted between the cylindrical casing member and the cover member and pressedly supported by resilient means.
 19. A compressor according to claim 18, wherein the volume of the pipe means is relatively small as compared to the volume of the silencing chamber.
 20. A compressor according to claim 19, wherein the silencing chamber is located at the junction of the cylinder blocks.
 21. A silencing chamber arrangement for a swash plate type compressor of the type having high pressure gas passageways located at opposite sides of a rotatable swash plate; said arrangement comprising a silencing chamber positioned between said high pressure gas passageways, a discharge port communicating with the silencing chamber for discharging gas from said silencing chamber, and detachable silencing communicating means for communicating each of said high pressure gas passageways with said silencing chamber, said silencing communicating means including resilient means for absorbing pressure pulsations therein.
 22. An arrangement according to claim 21, wherein said detachable silencing communication means includes a resilient coiled spring for each high pressure gas passageway positioned such that all of the gas in the associated high pressure gas passageway flows therethrough.
 23. An arrangement according to claim 22, wherein said coiled springs are interposed between a cover member of the compressor which delimits one side of the silencing chamber and a casing member of the compressor.
 24. An arrangement according to claim 21, wherein said detachable silencing communicating means includes a resilient member and a detachable pipe member, said pipe member having apertures through the side walls thereof through which the gas in the associated high pressure gas passageway flows.
 25. An arrangement according to claim 21, wherein said detachable silencing communicating means includes a resilient member for resiliently holding other parts of said communicating means in position, and wherein said high pressure gas passageways are located symmetrically with respect to the volumetric center of said silencing chamber. 